scholarly journals Inhibitory action of polyamines on protein kinase C association to membranes

1987 ◽  
Vol 247 (1) ◽  
pp. 175-180 ◽  
Author(s):  
M Moruzzi ◽  
B Barbiroli ◽  
M G Monti ◽  
B Tadolini ◽  
G Hakim ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Activation Process ◽  
Dependent Manner ◽  
Kinase C ◽  
Association Reaction ◽  
Dose Dependent ◽  
Inside Out

Physiological activation of protein kinase C requires the interaction of this enzyme with cellular membranes [Nishizuka (1986) Science 233, 305-312]. In the present work a reconstituted system of protein kinase C and human inside-out erythrocyte vesicles was utilized to study the effect in vitro of naturally occurring polyamines on the activation process of protein kinase C. The active membrane-associated complex was conveniently determined by its ability to bind radioactive phorbol ester with an exact 1:1 stoichiometry. The association reaction of the enzyme to membrane was rapid, being complete within 1 min at 25 degrees C. The addition of polyamines, particularly spermine, greatly decreased in a dose-dependent manner the amount of protein kinase C bound to membranes (i.e. in the activated form). The effect observed was quite specific, since it was dependent on the chemical structure of the polyamine and it was manifest at micromolar concentrations of the polycation; the order of potency was spermine greater than spermidine greater than putrescine. A characterization of this effect is presented and possible physiological implications are discussed.

Effect of glucocorticoid on prostaglandin F2α-induced prostaglandin E2 synthesis in osteoblast-like cells: inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2

1994 ◽  
Vol 131 (5) ◽  
pp. 510-515 ◽  
Author(s):  
Osamu Kozawa ◽  
Haruhiko Tokuda ◽  
Atsushi Suzuki ◽  
Jun Kotoyori ◽  
Yoshiaki Ito ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase A2 ◽  
Phospholipase C ◽  
Phospholipase A ◽  
Phosphoinositide Hydrolysis ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Kinase C ◽  
Dose Dependent

Kozawa O, Tokuda H, Suzuki A, Kotoyori J, Ito Y, Oiso Y. Effect of glucocorticoid on prostaglandin F2α-induced prostaglandin E2 synthesis in osteoblast-like cells: inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2. Eur J Endocrinol 1994;131:510–15. ISSN 0804–4643 It is well known that osteoporosis is a common complication of patients with glucocorticoid excess. We showed previously that prostaglandin (PG) F2α stimulates the synthesis of PGE2, a potent bone resorbing agent, and that the activation of protein kinase C amplifies the PGF2α-induced PGE2 synthesis through the potentiation of phospholipase A2 activity in osteoblast-like MC3T3-E1 cells. In the present study, we examined the effect of dexamethasone on PGE2 synthesis induced by PGF2α in MC3T3-E1 cells. The pretreatment with dexamethasone significantly inhibited the PGE2 synthesis in a dose-dependent manner in the range between 0.1 and 10 nmol/l in these cells. This effect of dexamethasone was dependent on the time of pretreatment up to 8 h. Dexamethasone also inhibited PGE2 synthesis induced by melittin, known as a phospholipase A2 activator. Furthermore, dexamethasone significantly inhibited the enhancement of PGF2α- or melittin-induced PGE2 synthesis by 12-O-tetradecanoylphorbol-13-acetate, known as a protein kinase C activator. In addition, dexamethasone significantly inhibited PGF2α-induced formation of inositol phosphates in a dose-dependent manner between 0.1 and 10 nmol/l in MC3T3-E1 cells. These results strongly suggest that glucocorticoid inhibits PGF2α-induced PGE2 synthesis through the inhibition of phosphoinositide hydrolysis by phospholipase C as well as phospholipase A2 in osteoblast-like cells. Osamu Kozawa, Department of Biochemistry, Institute for Developmental Research, Aichi Prefectural Colony, Kasugai, Aichi 480-03, Japan

14-3-3 Isotypes facilitate coupling of protein kinase C-ζ to Raf-1: negative regulation by 14-3-3 phosphorylation

2000 ◽  
Vol 345 (2) ◽  
pp. 297-306 ◽  
Author(s):  
Paulus C. J. VAN DER HOEVEN ◽  
José C. M. VAN DER WAL ◽  
Paula RUURS ◽  
Marc C. M. VAN DIJK ◽  
Wim J. VAN BLITTERSWIJK
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Complex Formation ◽  
Dependent Manner ◽  
Cos Cells ◽  
Kinase C ◽  
Pkc Ζ ◽  
Co Precipitation

14-3-3 Proteins may function as adapters or scaffold in signal-transduction pathways. We found previously that protein kinase C-ζ (PKC-ζ) can phosphorylate and activate Raf-1 in a signalling complex [van Dijk, Hilkmann and van Blitterswijk (1997) Biochem. J. 325, 303-307]. We report now that PKC-ζ-Raf-1 interaction is mediated by 14-3-3 proteins in vitro and in vivo. Co-immunoprecipitation experiments in COS cells revealed that complex formation between PKC-ζ and Raf-1 is mediated strongly by the 14-3-3β and -θ isotypes, but not by 14-3-3ζ. Far-Western blotting revealed that 14-3-3 binds PKC-ζ directly at its regulatory domain, where a S186A mutation in a putative 14-3-3-binding domain strongly reduced the binding and the complex formation with 14-3-3β and Raf-1. Treatment of PKC-ζ with lambda protein phosphatase also reduced its binding to 14-3-3β in vitro. Preincubation of an immobilized Raf-1 construct with 14-3-3β facilitated PKC-ζ binding. Together, the results suggest that 14-3-3 binds both PKC-ζ (at phospho-Ser-186) and Raf-1 in a ternary complex. Complex formation was much stronger with a kinase-inactive PKC-ζ mutant than with wild-type PKC-ζ, supporting the idea that kinase activity leads to complex dissociation. 14-3-3β and -θ were substrates for PKC-ζ, whereas 14-3-3ζ was not. Phosphorylation of 14-3-3β by PKC-ζ negatively regulated their physical association. 14-3-3β with its putative PKC-ζ phosphorylation sites mutated enhanced co-precipitation between PKC-ζ and Raf-1, suggesting that phosphorylation of 14-3-3 by PKC-ζ weakens the complex in vivo. We conclude that 14-3-3 facilitates coupling of PKC-ζ to Raf-1 in an isotype-specific and phosphorylation-dependent manner. We suggest that 14-3-3 is a transient mediator of Raf-1 phosphorylation and activation by PKC-ζ.

scholarly journals Phosphatidylinositol 3-Kinase-mediated Endocytosis of Renal Na+,K+-ATPase α Subunit in Response to Dopamine

1998 ◽  
Vol 9 (5) ◽  
pp. 1209-1220 ◽  
Author(s):  
Alexander V. Chibalin ◽  
Juleen R. Zierath ◽  
Adrian I. Katz ◽  
Per-Olof Berggren ◽  
Alejandro M. Bertorello
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Α Subunit ◽  
Kinase C ◽  
Dose Dependent ◽  
Α Subunits ◽  
K Activity ◽  
Phosphatidylinositol 3

Dopamine (DA) inhibition of Na+,K+-ATPase in proximal tubule cells is associated with increased endocytosis of its α and β subunits into early and late endosomes via a clathrin vesicle-dependent pathway. In this report we evaluated intracellular signals that could trigger this mechanism, specifically the role of phosphatidylinositol 3-kinase (PI 3-K), the activation of which initiates vesicular trafficking and targeting of proteins to specific cell compartments. DA stimulated PI 3-K activity in a time- and dose-dependent manner, and this effect was markedly blunted by wortmannin and LY 294002. Endocytosis of the Na+,K+-ATPase α subunit in response to DA was also inhibited in dose-dependent manner by wortmannin and LY 294002. Activation of PI 3-K generally occurs by association with tyrosine kinase receptors. However, in this study immunoprecipitation with a phosphotyrosine antibody did not reveal PI 3-K activity. DA-stimulated endocytosis of Na+,K+-ATPase α subunits required protein kinase C, and the ability of DA to stimulate PI 3-K was blocked by specific protein kinase C inhibitors. Activation of PI 3-K is mediated via the D1 receptor subtype and the sequential activation of phospholipase A2, arachidonic acid, and protein kinase C. The results indicate a key role for activation of PI 3-K in the endocytic sequence that leads to internalization of Na+,K+-ATPase α subunits in response to DA, and suggest a mechanism for the participation of protein kinase C in this process.

scholarly journals Regulation of prostaglandin synthesis by protein kinase C in mouse peritoneal macrophages

1989 ◽  
Vol 260 (2) ◽  
pp. 471-478 ◽  
Author(s):  
H J Pfannkuche ◽  
V Kaever ◽  
D Gemsa ◽  
K Resch
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Peritoneal Macrophages ◽  
Dependent Manner ◽  
Membrane Phospholipids ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Dependent Protein ◽  
Dose Dependent ◽  
Mouse Peritoneal Macrophages

Resident mouse peritoneal macrophages synthesized and released prostaglandins (PGs) when challenged with 12-O-tetradecanoylphorbol 13-acetate (TPA) or 1,2-dioctanoyl-sn-glycerol (DiC8). Both stimuli were found to activate Ca2+/phospholipid-dependent protein kinase C (PKC). 1-(5-Isoquinolinesulphonyl)-2-methylpiperazine (‘H-7’) and D-sphingosine, known to inhibit PKC by different mechanisms, were able to decrease the PKC activity of macrophages in a dose-dependent manner. Addition of either PKC inhibitor decreased PG synthesis and also the release of arachidonic acid (AA) from phospholipids induced by TPA or DiC8. Simultaneously TPA or DiC8 also decreased incorporation of free AA into membrane phospholipids of macrophages. AA incorporation could be restored, however, by pretreatment with the PKC inhibitors. Our results demonstrate an involvement of PKC in the regulation of PG synthesis in mouse peritoneal macrophages and provide further evidence that reacylation of released fatty acids may be an important regulatory step.

scholarly journals Nesfatin-1 Suppresses Cardiac L-type Ca2+ Channels Through Melanocortin Type 4 Receptor and the Novel Protein Kinase C Theta Isoform Pathway

2015 ◽  
Vol 36 (2) ◽  
pp. 555-568 ◽  
Author(s):  
Jiaoqian Ying ◽  
Yuan Zhang ◽  
Shan Gong ◽  
Zhigang Chang ◽  
Xiaofeng Zhou ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Ventricular Myocytes ◽  
Dependent Manner ◽  
The Novel ◽  
Inotropic Effects ◽  
Kinase C ◽  
Melanocortin 4 Receptor ◽  
Dose Dependent ◽  
Ca2 Channels

Background/Aims: Nesfatin-1 (NF-1), an anorexic nucleobindin-2 (NUCB2)-derived hypothalamic peptide, acts as a peripheral cardiac modulator and it can induce negative inotropic effects. However, the mechanisms underlying these effects in cardiomyocytes remain unclear. Methods: Using patch clamp, protein kinase assays, and western blot analysis, we studied the effect of NF-1 on L-type Ca2+ currents (ICa,L) and to explore the regulatory mechanisms of this effect in adult ventricular myocytes. Results: NF-1 reversibly decreased ICa,L in a dose-dependent manner. This effect was mediated by melanocortin 4 receptor (MC4-R) and was associated with a hyperpolarizing shift in the voltage-dependence of inactivation. Dialysis of cells with GDP-β-S or anti-Gβ antibody as well as pertussis toxin pretreatment abolished the inhibitory effects of NF-1 on ICa,L. Protein kinase C (PKC) antagonists abolished NF-1-induced responses, whereas inhibition of PKA activity or intracellular application of the fast Ca2+-chelator BAPTA elicited no such effects. Application of NF-1 increased membrane abundance of PKC theta isoform (PKCθ), and PKCθ inhibition abolished the decrease in ICa,L induced by NF-1. Conclusion: These data suggest that NF-1 suppresses L-type Ca2+ channels via the MC4-R that couples sequentially to the βγ subunits of Gi/o-protein and the novel PKCθ isoform in adult ventricular myocytes.

Spontaneous maturation in Bufo arenarum oocytes: participation of protein kinase C

Zygote ◽  
1996 ◽  
Vol 4 (04) ◽  
pp. 257-262 ◽  
Author(s):  
L. Zelarayán ◽  
J. Oterino ◽  
M.I. Bühler
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Respiratory Activity ◽  
Follicle Cells ◽  
Dependent Manner ◽  
Germinal Vesicle Breakdown ◽  
Kinase C ◽  
Bufo Arenarum

SummaryAlthough progesterone is the maturation inducer in amphibians, it has been demonstrated that inBufo arenarumoocytes resumed meiosis with no need of exogenous hormonal stimulus if derived of their enveloping, follicle cells. This phenomenon, called spontaneous maturation, is quite rare in amphibians. InB. arenarum, spontaneous maturation took place only in oocytes obtained during the reproductive period (spring-summer). During this period the oocytes also demonstrated a respiratory activity characteristic of mature oocytes. Interestingly, full-grownB. arenarumoocytes always responded to progesterone regardless of the season in which they were obtained and of their respiratory activity. The disposition of oocytes competent or not competent to mature spontaneously provides a useful system for the study of molecular mechanisms involved in the maturation process. The data presented here indicate that the activation of protein kinase C (PKC) induces germinal vesicle breakdown (GVBD) in denuded oocytes unable to mature spontaneously (winter oocytes) and is involved in the in vitro spontaneous maturation ofB. arenarumfull-grown oocytes. The inhibition of PKC by 1-(5-isoquinolynyl-sulphonyl-2-methyl-piperazine (H-7) impeded spontaneous maturation in a dose-dependent manner, thus supporting the participation of the PKC pathway during this process. Interestingly phorbol 12-myristate-13-acetate (PMA)-induced GVBD is inhibited by the incubation of the oocytes in dibutyryl cAMP (dbcAMP), indicating that both pathways, PKC and protein kinase A (PKA), are related at a certain point. However, spontaneous GVBD is less sensitive than PMA-induced GVBD to dbcAMP. This fact would support the suggestion that in spontaneous GVBD mechanisms different from activation of PKC are at work.

scholarly journals G-protein βγ subunits antagonize protein kinase C-dependent phosphorylation and inhibition of phospholipase C-β1

1997 ◽  
Vol 326 (3) ◽  
pp. 701-707 ◽  
Author(s):  
Irene LITOSCH
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
G Protein ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Negative Feedback Regulation ◽  
Kinase C ◽  
Stimulation Of

Protein kinase C (PKC) isoforms phosphorylated phospholipase C-β1 (PLC-β1) in vitro as follows: PKCα ≫ PKCϵ; not PKCζ. PLC-β3 was not phosphorylated by PKCα. G-protein βγ subunits inhibited the PKCα phosphorylation of PLC-β1 in a concentration-dependent manner. Half-maximal inhibition occurred with 500 nM βγ. G-protein βγ subunits also antagonized the PKCα-mediated inhibition of PLC-β1 enzymic activity. PKCα, in turn, inhibited the stimulation of PLC-β1 activity by βγ. There was little effect of PKCα on the stimulation of PLC-β1 by αq/11–guanosine 5′[γ-thio]triphosphate (GTP[S]). These findings demonstrate that G protein βγ subunits antagonize PKCα regulation of PLC-β1. Thus βγ subunits might have a role in modulating the negative feedback regulation of this signalling system by PKC.

The role of protein kinase C in LHRH-induced LH and FSH release and LHRH self-priming in rat anterior pituitary glands in vitro

1988 ◽  
Vol 116 (2) ◽  
pp. 231-239 ◽  
Author(s):  
M. S. Johnson ◽  
R. Mitchell ◽  
G. Fink
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Esters ◽  
Polymyxin B ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Kinase C ◽  
Pituitary Glands

ABSTRACT We have investigated the role of protein kinase C (PKC) in LHRH-induced LH and FSH secretion and LHRH priming. Hemipituitary glands from pro-oestrous rats were incubated with agents known to affect PKC and with or without LHRH, during which time the secretion of gonadotrophins was measured. Phorbol esters and phospholipase C, activators of PKC, released LH and FSH in a concentration-dependent manner and potentiated the LHRH-induced secretion of gonadotrophins in parallel with their ability to release these hormones alone. Inhibitors of PKC had either no effect on LH release (1-(5-isoquinolinesulphonyl)-2-methylpiperazine hydrochloride) or they augmented LHRH-induced gonadotrophin release (polymyxin B and 8-(N,N-diethylamino) octyl-3,4,5-trimethoxybenzoate). Neither the activators nor the inhibitors of PKC, when present with LHRH, caused any change in LHRH priming, even though the activators alone produced a release of gonadotrophins that showed a temporal pattern similar to that produced by LHRH priming. The profiles of effects on LH and FSH secretion were always qualitatively similar. These results show that PKC may be involved in general regulation of gonadotrophin release but that it is not important in acute responses to LHRH nor in LHRH self-priming. J. Endocr. (1988) 116, 231–239

Role of protein kinase C in the pigment cell of the lizard (Anolis carolinensis)

1987 ◽  
Vol 112 (2) ◽  
pp. 283-287 ◽  
Author(s):  
A. M. Lucas ◽  
A. J. Thody ◽  
S. Shuster
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adenylate Cyclase ◽  
Pigment Cell ◽  
Anolis Carolinensis ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Kinase C

ABSTRACT The role of protein kinase C in melanosome dispersion was examined using the melanophores of the lizard Anolis carolinensis and an in-vitro rate method of bioassay. The phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which directly activates protein kinase C, was able to potentiate the melanophore response to α-MSH in a dose-dependent manner. Similarly, the stimulatory response to forskolin, which activates the adenylate cyclase catalytic subunit, was also potentiated by TPA. The response of the melanophore to cyclic AMP, however, remained unaltered by any dose of TPA. We thus propose that the potentiation of α-MSH potency by TPA is through an interaction of protein kinase C with adenylate cyclase and, more specifically, that this interaction may be at the level of the linkage of the nucleotide regulatory subunit Ns with the catalytic moiety C of adenylate cyclase. J. Endocr. (1987) 112, 283–287

Sign in / Sign up

Export Citation Format

Share Document